Ahead of a Ranking points-laden week at the US PGA Championship, europeantour.com examines the possible scenarios as to who could claim the World Number One spot along with the Wanamaker Trophy this week on Kiawah Island.

Yes, in the complex realm of the Official World Golf Rankings it’s sometimes worth breaking the potential outcomes in the three-way World Number One battle down into digestible chunks, so that’s what our top statisticians have done for you.

The three players in this game of Number One cat and mouse? Luke Donald – currently World Number One, Tiger Woods – currently Number Two, and Rory McIlroy – currently Number Three.

Donald has – as of this week – spent a combined 56 weeks as World Number One since first achieving the impressive feat after his dramatic play-off triumph at the 2011 BMW PGA Championship at Wentworth, a total accrued after four stints at the top.

Woods, meanwhile, of course holds the undisputed record of 623 weeks spent at World Number One, recently rose back to World Number Two, and is once again knocking on the door at the peak of the World Ranking.

Northern Irish sensation McIlroy usurped his Ryder Cup team-mate Donald thanks to victory at the US PGA Tour’s Honda Classic in February, a coronation in Florida that proved to be the prologue to an extraordinary two months in the Rankings as the World Number One baton was passed back and forth between Donald and the 23 year old a further five times, culminating once again at The European Tour’s flagship event at Wentworth in May this year.

Donald, of course, retained both his BMW PGA Championship crown and – in a wonderful piece of symmetry – also regained the World Number One spot, just as he had done 12 months earlier.

And now, three months down the line, any one of the aforementioned trio can leave this South Carolina paradise as King of the Castle.

So, let’s put it simply: the key permutations of how the battle for the Number One spot could unfold this week:

- Tiger Woods and Rory McIlroy can both reach World Number One this week while even a win for Westwood would not quite be enough to see him to ascend to the summit of golf again

- If Woods wins he goes to World Number One regardless of any of his competitors’ performances

- McIlroy will go to Number One with a win at Kiawah if Donald finishes lower than tied second with one player only, or worse

- Should McIlroy finish the US PGA alone in second place he could go to Number One if Donald misses the cut and the winner is anyone else but Woods

- If Woods finishes second alone he would go to Number One so long as Donald finishes outside of the top five and McIlroy isn’t the lucky man to be hoisting the Wanamaker Trophy come Sunday evening